Continuous Profiler

It's a simple implementation of a continuous profiler that runs in a browser context. It facilitates the JS Self-Profiling API.

The built-in JS profiler will run as long as it has space in the sample buffer. In practice, this means that there is a limited duration that a single profiler can profile. This package implement continuous profiler which manages multiple JS profiler instances to profile user session without any duration limit.

Prerequisites

At the time of writing this README, the JS Self-Profiling API is available in Chrome 94+, Edge 94+, and Opera 80+ browsers.

It also requires Document-Policy: js-profiling=true HTTP header for the HTML document.

Installation

This package is available on npm:

npm install continuous-profiler # for npm
yarn add continuous-profiler # for yarn

Usage

Please, ensure that you set up the Document-Policy HTTP header. To use the profiler, import it like a regular module and call the .start() method.

import { ContinuousProfiler } from "continuous-profiler";

const profiler = new ContinuousProfiler(
    (trace) => {
        sendTrace(JSON.stringify(trace));
    },
    {
        sampleInterval: 10, // sample every 10ms
        collectInterval: 10000 // collect every 10s
    }
);
profiler.start();
window.addEventListener('unload', () => profiler.stop());

The first argument passed to the ContinuousProfiler constructor is a callback that will be called every 10 seconds with a trace.

The second argument are options where you can specify sample and collect intervals.

License

MIT